CH 4 ConnectPlus Questions

During the mitotic phase called ________, chromosomes condense, the nuclear envelope disappears, spindle fibers grow, and centrioles migrate to the poles of cell.

Prophase

True/False: Genes produce their products nonstop, 24-hours a day.

False - Recall that genes can be turned on and off from day to day, even hour to hour, as their products are needed or not, and many genes are permanently turned off in any given cell. Some genes for example are present but inactive in some cells.

______ are the organelles that process coded genetic messages and assemble amino acids into proteins.

Ribosomes

Describe ribosomes:

Ribosomes are made up of subunits that come together only when translating mRNA. Ribosomes are found in the cytosol and on rough ER. Each ribosome is composed of several enzymes and ribosomal RNA (rRNA) molecules.

Match the base triplet of DNA to the amino acid specified by the genetic code. CCA:

Glycine

Daughter chromosomes migrate to opposite poles of the cell during which phase of mitosis?

Anaphase

Susie is not color-blind, but she transmitted a color-blindness gene to her son. She is said to be a _______ of the color blindness gene.

Carrier

Where is RNA usually found?

Cytoplasm

Match each protein with its role during DNA replication. DNA polymerase:

Reads about 100 nitrogenous bases per second and matches them with complementary free nucleotides.

Cytokinesis is the division of the cells _______ to form two cells.

Cytoplasm

Match each process to the location where it usually occurs: Translation:

Cytoplasm

Which of the following are nucleic acids?

RNA & DNA

Anticodons are found on which type of molecule?

tRNA

Match each protein with its role during DNA replication. DNA Helicase:

Opens the DNA helix exposing the nitrogenous bases

codons:

The genetic code is expressed as a sequence of codons

This circle is divided into lettered quadrants. Each one represents a phase of the cell cycle. Match the letter of each quadrants with the cell cycle phase that it represents. G1-1st gap phase (growth and normal metabolic roles) -

Two gaps take place. The 1st is after mitosis, the second is after the synthesis phase.

This circle is divided into lettered quadrants. Each one represents a phase of the cell cycle. Match the letter of each quadrants with the cell cycle phase that it represents. M Mitotic phase -

You can tell by the dividing nucleus in the image that this is the mitotic phase.

place the events of protein synthesis in order.

1. The ribosome binds mRNA 2. A tRNA anticodon binds to a complementary mRNA codon. 3. A new amino acid is linked to the growing peptide chain. 4. The tRNA is released from the ribosome, and is now available to pick up another amino acid.

The components of nucleotides:

A sugar (ribose or deoxyribose) A phosphate group A nitrogenous base

Match each nitrogenous base with its classification Purine:

Adenine, Guanine

Refer to the table. Match the base triplet of DNA to the amino acid specified by the genetic code. CGT

Alanine

Which of the following statements are true regarding introns?

An intron is a portion of mRNA that must be removed before translation. An intron is a portion of mRNA that does not code for protein. NOT: An intron is a portion of mRNA that undergoes translation in the cytoplasm.

Which of the following refers to a 3-base sequence found in tRNA?

Anticodon

Chromosome X and Y are called the sex chromosomes because they determine the sex of an individual; all the others are called ________.

Autosomes

Describe telophase:

Chromatids cluster on each side of the cell. A nuclear envelope reappears. Recall that during telophase, chromatids are gathered at the poles, chromatin decondenses that new nuclear envelopes form, new nucleoli appear, and the spindles vanish.

During translation, mRNA:

Contains a cap that acts like a passport, permitting it to pass through a nuclear pore and tells a ribosome where to begin translation Carries the genetic code from the nucleus to the cytoplasm.

RNA interpret the code in DNA and use the instructions to synthesize proteins. RNA works mainly in the ______, while DNA remains in the _______.

Cytoplasm; nucleus

Match each nitrogenous base with its classification Pyrimidine:

Cytosine

Transcription is the process of copying genetic instructions from _______ to RNA.

DNA

Which of the following best summarizes the role of DNA in protein synthesis?

DNA contains the genetic code that determines the amino acid sequence of proteins.

Following transcription, only some portions of the mRNA code for the final protein. The sections of mRNA that contain necessary code are called _______, whereas the mRNA sections that do not code for the final protein are called _______.

Exons, introns

Since there are no genes coding for carbohydrates, nucleic acids, or lipids, how do cells produce them?

Genes encode enzymes that synthesize these products.

An individual with different alleles at a loci on homologous chromosomes is said to be _______ for that trait.

Heterozygous

Refer to the table. Match the base triplet of DNA to the amino acid specified by the genetic code. GTA:

Histidine

One member of each _______ pair of chromosomes is inherited from the individual's mother and the other from the father.

Homologous

Translation occurs in three steps. Place the steps in order from what happens first to what happens last.

Initiation, elongation, termination

The _______ bases in DNA are adenine, cytosine, guanine, and thymine.

Nitrogenous

Name the subunits that comprise a molecule of DNA:

Nucleotides

Match each process to the location where it usually occurs: Transcription:

Nucleus

The combination of alleles present is referred to as a person's genotype, whereas his/her _______ is the observable traits that result from his/her genes.

Phenotype

Put the steps of mitosis in the correct

Prophase, Metaphase, Anaphase, Telophase

Match each organelle with its role in processing of proteins to be exported by the cell. Rough endoplasmic reticulum:

Proteins are synthesized by ribosomes bound to it. It packages proteins into clathrin coated transport vesicles.

Indicate the difference between DNA and RNA.

RNA contains a sugar called ribose whereas DNA contains a sugar called deoxyribose. RNA is much smaller. DNA, by contrast, averages more than 100 million base pairs long. RNA consists of only one nucleotide chain whereas DNA is a double helix.

The process by which a cell makes a copy of its DNA, creating two new strands is referred to as?

Replication

Each daughter DNA consists of one new strand (synthesized from free nucleotides) and one old strand (conserved from the parental DNA). This process is called _______ replication.

Semiconservative

The X and Y chromosomes are referred to as?

Sex Chromosomes

Egg and sperm cells (or their precursors) are called germ cells. All other cells in the body are called _______ cells.

Somatic

What occurs during the G1 phase of the cell cycle?

The cell synthesizes proteins, grows, and accumulates the materials needed to replicate its DNA in the next phase.

The G0 phase of the cell cycle:

The duration of this phase is variable (for some cells it may last days, years, or the rest of ones life. During this phase cells leave the cell cycle for a "rest" and cease to divide. An inability to stop cycling and enter G0 is characteristic of cancer cells.

True/ False: Some cells leave the cell for a "rest" and cease to divide for days, years, or the rest of one's life, and some cells like stomach and skin divide rapidly.

True

In the nucleus of a typical human cell, there are 46 filaments. Which term refers to one of these structures?

Chromosomes

Which is characteristic of codons?

Code for amino acids Are three-base sequences of mRNA Are complementary to anticodons.

Alternative forms of a gene are known as _______.

Alleles

mRNA is short for ______ RNA.

Messenger

Put the events of DNA replication in order starting with what happens first:

1. DNA helicase unwinds the double helix. 2. DNA polymerase forms 2 new strands: one continuous and one as segments. 3. DNA ligase closes the gaps between newly formed segments. 4. Two DNA double helices result (each with a new and a parental strand).

Place in order the sequence of events during protein processing and secretion:

1. Protein formed by ribosomes on RER. 2. Protein packaged into transport vesicles, which bud from ER. 3. Transport vesicles unload protein into Golgi complex. 4. Golgi complex modifies protein structure. 5. Secretory vesicles release protein by exocytosis.

Which molecules participate in DNA replication?

DNA polymerase, DNA, DNA helicase, DNA ligase

The genetic code in ______ specifies which type of ______ a cell can make.

Deoxyribonucleic acid (DNA); proteins

What are the functions of mitosis?

It allows development of an individual, composed of some 50 trillion cells, from a one-celled fertilized egg, it allows growth of all tissues and organs after birth, it repairs damaged tissue, and it replaces the cells that die with new ones.

Deoxyribonucleic acid (DNA):

It contains a sugar called deoxyribose, it contains nitrogenous bases A, T, C, G: It consists of two nucleotide chains (double helix); it functions in the nucleus; it codes for synthesis of RNA and protein.

Ribonucleic acid (RNA):

It contains a sugar called ribose; it contains nitrogenous bases A, U, C, G; it consists of one nucleotides chain; it functions mainly in the cytoplasm; it carries out the instructions in the DNA.

Match each organelle with its role in processing of proteins to be exported by the cell. Golgi complex:

It modifies proteins, often by adding carbohydrate chains. It packages some proteins into lysosomes and some into secretory vesicles that are secreted through exocytes.

Match each protein with its role during DNA replication. DNA Ligase:

Joins the newly synthesized segments of DNA.

The location of a particular gene on a chromosome is called its _______.

Locus

Indicate which of the following is not a part of interphase.

M

The form of cell division in which a cell divides once and produces two genetically identical daughter cells is known as _______.

Mitosis

A cell replicates its nucleus and then forms two new daughter cells during which phase of the cell cycle?

Mitotic phase (M) - Recall that during mitosis a cell divides once and produces two genetically identical daughter cells. The cell cycle of interphase (G1, S, and G2) and the mitotic phase.

Any change in the structure of a chromosome or a DNA molecule, often resulting in a change of structure or function in the protein produced, is known as a _________.

Mutation

The structure of DNA is commonly described as a double helix that resembles a spiral staircase.

The nitrogenous bases face the inside and hold the two backbones with hydrogen bonds. Each sidepiece is sugar-phosphate backbone composed of phosphate groups alternating with the sugar deoxyribose.

This circle is divided into lettered quadrants. Each one represents a phase of the cell cycle. Match the letter of each quadrants with the cell cycle phase that it represents. S Phase- Synthesis phase (DNA replication) -

The synthesis phase takes place between two gaps phases.

Recessive alleles:

Their expression is masked in the presence of a dominant allele. They are expressed only when present on both of the homologous chromosomes.

This circle is divided into lettered quadrants. Each one represents a phase of the cell cycle. Match the letter of each quadrants with the cell cycle phase that it represents. G2- 2nd gap phase (growth and preparation for mitosis) -

There are two gap phase. G1 before DNA replication, G2 is after.

Why are sperm and egg cells said to be haploid?

They contain only 23 unpaired chromosomes.

Refer to the table. Match the base triplet of DNA to the amino acid specified by the genetic code. TGC:

Threonine

Match each nitrogenous base with its classification Pyrimidine:

Thymine

The process of reading an MRNA molecule and synthesizing the protein encoded in its nucleotide sequence is known as ________.

Translation

A base _______ is a consecutive sequence of three DNA nucleotides that codes for one amino acid.

Triplet